"When I started my career at the Centers for Disease Control and Prevention in the mid-1980s, AIDS was a newly discovered virus and people counseled me to stay away. They said it was just a medical curiosity that would be quickly solved and never have major public health importance.

Since HIV – the disease that causes AIDS – was identified in 1981, more than 60 million people have been infected – and 25 million have died AIDS-related deaths, mostly in low- and middle-income countries.

In developed countries like the United States your earning potential is often based on the number of diplomas you have. But in rural Malawi, completing even a primary education is one of the most precious things anyone can achieve.